1. Field of the Invention
The present invention relates to an engine control apparatus for a motorcycle, and particularly relates to an engine control apparatus capable of detecting an abnormality of the control apparatus.
2. Description of Related Art
An electronic throttle valve controls an opening degree of a throttle valve by an electronic control to control an intake amount of an engine (internal combustion engine) to realize low emission gas and low fuel cost. Such a construction is already adopted in portions of passenger vehicles.
In adopting an electronic throttle valve for a motorcycle, a drive motor for controlling an opening degree of the throttle valve needs to be arranged compactly while avoiding interference with a fuel injection valve arranged at an intake path. Therefore, although a compact electronic throttle control apparatus mountable to a motorcycle is proposed in prior art such as JP-A-2002-256895, an electronic throttle control apparatus has not been adopted yet in motorcycles due to their inherent restrictions.
On the other hand, an electronic throttle control mounted to an automobile executes a system control by CPU (Central Processing Unit) and detects an abnormality of the system in combination with a drive control of an engine (ignition control, fuel injection control or the like).
Generally, detection of an abnormality of a system is executed by constituting a CPU as a double system and comparing control values calculated by using the same data. See, for example, JP-A-2002-371897.
Even when an engine control apparatus for an automobile such as that disclosed in JP-A-2002-371897 is applied to a motorcycle, there is a possibility of great vehicle behavior changes during system abnormality.